Top 23 Email Open-Source Projects

  • N1

    :love_letter: An extensible desktop mail app built on the modern web. Forks welcome!

  • awesome-falsehood

    😱 Falsehoods Programmers Believe in

    Project mention: 15 minute cities | | 2023-04-09
  • Appwrite

    Appwrite - The Open Source Firebase alternative introduces iOS support . Appwrite is an open source backend server that helps you build native iOS applications much faster with realtime APIs for authentication, databases, files storage, cloud functions and much more!

  • novu

    The open-source notification infrastructure with fully functional embedded notification center

    Project mention: What's New in Novu 0.15.0? | | 2023-05-24

    There is work ongoing for Email Webhook Provider. You can follow the commits here

  • PHPMailer

    The classic email sending library for PHP

    Project mention: Sending Text Messages | | 2023-05-03

    I found I have good experiences with a real email address provided by my domain/web host, and then I use the PHPMailer Class to send the message with the appropriate headers and what not.

  • Nodemailer

    ✉️ Send e-mails with Node.JS – easy as cake!

    Project mention: Setting up an auto-email micro function for Firebase RTDB | | 2023-05-25

    For email, we’re going to use the very popular nodemailer package. Throw an npm install nodemailer and import it at the top of our function, and we’ll create our transporter instance:

  • MJML

    MJML: the only framework that makes responsive-email easy

    Project mention: Learn serverless on AWS step-by-step - Emails | | 2023-05-26

    Be careful when using CSS, some properties like flex ⚠️ are not supported by all email clients. You can check this website to see which properties are supported by which email clients. Another solution is to use a CSS framework that will do the hard compatibility work for you. I use MJML, in my in-depth article about SES, I explain how to use it to create responsive emails.

  • Mailspring

    :love_letter: A beautiful, fast and fully open source mail client for Mac, Windows and Linux.

    Project mention: Mail client | | 2023-03-13



    ONLYOFFICE Docs — document collaboration in your environment. Powerful document editing and collaboration in your app or environment. Ultimate security, API and 30+ ready connectors, SaaS or on-premises

  • Postal

    ✉️ A fully featured open source mail delivery platform for incoming & outgoing e-mail

    Project mention: Breaking Free: How I Self-Hosted My SMTP Server with Haraka. Send thousands of emails per second at the cost of pennies. | | 2023-05-22

    Previously I’ve used Postal, which is not simple but okay. Can I do better? Isn’t why I’m writing this?!

  • responsive-html-email-template

    A free simple responsive HTML email template

    Project mention: Any one try Maizzle? | | 2022-10-31

    Ended up using this: It seems to do that job.

  • Mail-in-a-Box

    Mail-in-a-Box helps individuals take back control of their email by defining a one-click, easy-to-deploy SMTP+everything else server: a mail server in a box.

    Project mention: Self-hosted email? | | 2023-05-25
  • MailHog

    Web and API based SMTP testing

    Project mention: Docker + email setup | | 2023-03-28

    Does it say it's being send on localhost or on production? How is it "saying" it's being sent. We just setup mailhog to test emails for local development.

  • Listmonk

    High performance, self-hosted, newsletter and mailing list manager with a modern dashboard. Single binary app.

    Project mention: Umsetzung von E-Mail Aktion | | 2023-04-06
  • Mailpile

    A free & open modern, fast email client with user-friendly encryption and privacy features

    Project mention: [Self Hosted] Selbst gehostete Mailserver: mailcow, mailinabox, mailU... hast du sie (eingehend) getestet? Ihre Meinung und Ratschläge hier, danke! | | 2023-04-27
  • k-9

    K-9 Mail – Open Source Email App for Android

    Project mention: Thunderbird published its 2022 Financial Report, 6M$ in donations | | 2023-05-11
  • Mailcow

    mailcow: dockerized - 🐮 + 🐋 = 💕

    Project mention: Self-hosted email? | | 2023-05-25

    Have a look at mailcow. Been running it in a VPS for several years now and it's very reliable.

  • MailCatcher

    Catches mail and serves it through a dream.

    Project mention: New Mailcatcher docker image using Alpine 3.16.1 | | 2022-08-02

    I just upgraded to Alpine Linux 3.16.1 This is an important upgrade as it fixes 2 major issues: - busybox CVE-2022-30065 - openssl CVE-2022-2097 Related information: Mailcatcher as a docker image using Alpine Linux 3.16.1: Github repo: Mailcatcher:

  • Mautic

    Mautic: Open Source Marketing Automation Software.

    Project mention: Launch HN: Dittofeed (YC S22) – open-source customer engagement platform | | 2023-05-24
  • CssToInlineStyles

    CssToInlineStyles is a class that enables you to convert HTML-pages/files into HTML-pages/files with inline styles. This is very usefull when you're sending emails.

  • alertmanager

    Prometheus Alertmanager

    Project mention: My Raspberry Pi 4 Dashboard | | 2023-01-10

    - Alert Manager

  • MailKit

    A cross-platform .NET library for IMAP, POP3, and SMTP.

    Project mention: System.Net.Mail.SmtpClient is not recommended anymore; what is the alternative? | | 2023-04-25

    Looks like Mailkit is the way to go for open source solutions.

  • Tutanota makes encryption easy

    Tutanota is an email service with a strong focus on security and privacy that lets you encrypt emails, contacts and calendar entries on all your devices.

    Project mention: ⟳ 3 apps added, 54 updated at | | 2023-05-28

    Tutanota (version 3.112.15): Encrypted email & calendar service - easy to use, secure by design.

  • Mailtrain

    Self hosted newsletter app

    Project mention: Mxroute Mailing list | | 2023-04-19
  • frappe

    Low code web framework for real world applications, in Python and Javascript

    Project mention: Looking for open-source enthusiast programmers | | 2022-12-21

    ERPNext and Frappe Framework.

  • CodiumAI

    TestGPT | Generating meaningful tests for busy devs. Get non-trivial tests (and trivial, too!) suggested right inside your IDE, so you can code smart, create more value, and stay confident when you push.

NOTE: The open source projects on this list are ordered by number of github stars. The number of mentions indicates repo mentiontions in the last 12 Months or since we started tracking (Dec 2020). The latest post mention was on 2023-05-28.

Email related posts


What are some of the best open-source Email projects? This list will help you:

Project Stars
1 N1 24,738
2 awesome-falsehood 20,732
3 novu 20,691
4 PHPMailer 19,554
5 Nodemailer 15,626
6 MJML 15,283
7 Mailspring 14,134
8 Postal 12,709
9 responsive-html-email-template 12,200
10 Mail-in-a-Box 12,088
11 MailHog 12,025
12 Listmonk 10,055
13 Mailpile 8,738
14 k-9 7,956
15 Mailcow 6,496
16 MailCatcher 5,949
17 Mautic 5,842
18 CssToInlineStyles 5,701
19 alertmanager 5,700
20 MailKit 5,372
21 Tutanota makes encryption easy 5,318
22 Mailtrain 5,253
23 frappe 5,154
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